Small, monochrome dot matrix displays are used in a variety of consumer products such as VCRs, telephones, electronic musical instruments, microwave ovens and security control panels. Such displays usually have about two to four lines of text with sixteen to twenty characters per line. The displays typically utilize LCD technology.
These dot matrix displays may typically use a five column wide by seven row high matrix to form each character. Each character is normally defined to use all available pixels. Thus, each character is seven pixels high by five pixels wide. Characters are normally designed into the LCD panel hardware or are produced subject to software control of the pixel drivers.
It is essential that users be able to quickly recognize and differentiate types of information presented on such displays. In particular, labels for buttons or softkeys, adjacent to the display should be visually distinct from instructions or status information presented in the display. Since small dot matrix displays are typically monochrome, colors cannot be used for such a purpose. Further, since all available pixels are used to form each character, underlining may not be used for emphasis, such as is done on a CRT monitor.
One approach for providing emphasis to screen information has been to incorporate predefined words, known as annunciators, in the display. Fixed annunciators are provided in certain areas of the display aside from the usual program or hardware driven text characters defined by the pixel matrix. To provide emphasis, the characters of the annunciator are typically of a different size than the text characters defined by the pixel matrix. Typically, annunciators are turned "on" when their use is available, at which time they are visible on the display. Alternatively, annunciators are turned "of" and are substantially "invisible" when their use is unavailable. Each annunciator must be placed on the display in a unique position, i.e., no annunciator can overlap another annunciator. Due to the small size of the LCD panel, the number of annunciators which may be used is restricted. Further, such annunciators are fixed and must be embedded during the manufacturing process. If the manufacturer later decides that the annunciators are not correct, are confusing or otherwise wishes to change the annunciators, new display panels must be manufactured to embed the new words.
Another way to highlight information on limited dot matrix displays is to "blink" the character, i.e., turn the character's pixels on and off. The blinking character technique is often used in the following manner. In many cases, the limited dot matrix displays, in conjunction with the hardware they are associated with, offer options on the display to help the user accomplish certain tasks. These options are typically accessed by pressing two or more hardware buttons or softkeys, one a cursor key to move through the options and another an enter key to select the option. When moving through possible choices, usually the left-most word is highlighted first. Each time the cursor key is pressed, the next word to the right is highlighted. When the option highlighted is the one the user wishes to select, the user presses the enter key. Highlighting is accomplished by "blinking" the characters. Product research has shown that users are frequently confused by this type of display because it is often difficult to ascertain what option is actually being selected.
Accordingly, there is a need for a means to more clearly highlight and display information presented on limited pixel displays.